Another large demonstration follows the G20

Protesters held another 1,000-strong demonstration in downtown Toronto on Monday, rallying at police headquarters, City Hall and Queen's Park a day after police conducted mass arrests in the city.

Some later made their way to the temporary jail where an unknown number of people were still being held. But police blocked their path en route.

The crowd appeared to be drawn from all walks of life, marching peacefully and chanting "justice now" as they went.

"I have the right to peaceful assembly," one placard read.

Many protesters complained that police had mistreated those who were detained in mass arrests over the weekend, and that they had overstepped their authority.

The demonstration began as at least 1,000 people gathered outside police headquarters on College Street around 5:30 p.m.

One man said he had been held at what he called "Torontonamo Bay," a temporary detention centre, for failing to provide identification to police.

A woman who identified herself only as Zoe told CP24's George Lagogiannis that the money spent on the G8 and G20 summits "could have been used to end homelessness in this city."

Three rows of police lined the street in front of the building. Some officers had arrived on TTC buses, others by bicycle. They made one arrest in a nearby alley as they bolstered security in the lead-up to the demonstration.

The crowd eventually moved south down University Avenue before turning east on Queen Street West, where they were reportedly blocked by police. They made their way across Nathan Phillips Square to City Hall before backtracking up University Avenue again.

More than 900 people have been arrested since June 18 as a result of the mayhem and vandalism that occurred on the weekend. More than 600 of those arrests occurred in the past two days.

One of the most contentious events of the weekend took place on Sunday evening, when large groups of riot police trapped several hundred people at Queen Street West and Spadina Avenue in the pouring rain.

Police claim they had information that a group of protesters using black bloc tactics may have been in the crowd. They made an estimated 100 arrests before the crowd was allowed to disperse hours later.

In a statement released on Monday, the Toronto Community Mobilization Network said that over the past two days, those detained "have been denied access to lawyers, telephones, food and water, and held in deplorable conditions in makeshift steel cages."

"We need to get our people out. We need to take our city back from the armed fortress that it has been turned into."

Toronto Police Chief Bill Blair said the extensive security operation for the G20 summit was based on knowledge "of the capacity and the intent of some of these criminals."

"Many hundreds of people came to Toronto, not to protest, not even to impact the summit. They came to get on television by smashing windows and burning cars," he told CP24 on Monday.

"In that respect they were successful, but they'll be held accountable for their criminal conduct."

Mayor David Miller has also defended the conduct of police on the weekend.

CTV Toronto's Paul Bliss said as of Monday morning, many people were waiting outside the temporary detention centre on Eastern Avenue for their loved ones to be released.

Special courts have been set up to process prisoners, but the high volume has made for slow going.

Bliss said many people coming out of the detention centre said they didn't know it was a crime to wear black downtown.

On Saturday, a peaceful protest organized by the labour movement moved out from Queen's Park.

An organized group of vandals using so-called Black Bloc tactics emerged from the crowd -- and mayhem ensued.

For about 90 minutes, the vandals damaged banks and coffee shops. No damage total is available yet.

In response, the police conducted raids and arrests at the University of Toronto, picking up people who had travelled here from Quebec. That province has an active militant anarchist scene.

On Sunday, police were actively stopping and questioning young people on downtown streets. They continued making arrests.

There were police-demonstrator clashes outside the detention centre, leading to more arrests and officers firing tear gas pellets.